Replace the PVC valve and now ?

[gschretter]

I am running a custom air intake on my Chevy 350 so I do not have a hook up for the hose running from the valve cover to the air filter.

In order to pass emissions in TEXAS I have to have it hooked up.

So I ran a hose from the valve cover to a port on the intake.

I replace my PVC valve and the hose running to the carb.

Now I have tons of vaccum in the valve covers. When I take off the oil cap I feel like it is going to suck me in.

1. Will this hurt my engine ?
2. Would this make my emissions lower ? Since now I am sucking in all that unburnt gas from the valve covers back into the intake.

Thanks for any help you can provide.

[jimss454]

Does TX only require an annual inspection? If so, you need to get rid of your new connection and just plug in one of those chrome breather caps that can be found at auto parts stores in the performance parts section. (With the PCV valve on the other valve cover connected to it's vacuum port). The setup you have now is not good for your engine. You have tons of vacuum when you disconnect the filler cap or either fitting (PCV or your new connection), but when both are hooked up, you are not getting any flow of fresh air through your crankcase or valve covers, as the 2 vacuum connections will "cancel each other out" with equal vacuum. Yes, there will be high vacuum, but there will be no cleansing airflow thru the engine. The PCV is supposed to suck fresh air through the engine, in one valve cover, through the crankcase, then out the other V.C. This purges the oil vapors, unburned fuel vapors, condensation, and blow-by gasses (combustion by-products). Without this flow, you are accumulating all this nasty stuff in your engine, and much of it condenses and mixes with the oil. The resulting acids will etch cylinder walls & reduce your oil's ability to lubricate. Also, you will form sludge, even though todays oils are terrific at minimizing the nasty stuff. Many race cars have high-vacuum setups on their crankcases to improve ring seal, but they get rebuilt often, and don't have to go 100,000 miles. You need vacuum on the PCV side, and a source of CLEAN air at (or close to) atmospheric pressure at the other valve cover. That is why the factory setup takes air from inside the air cleaner. Just reconnect your new setup right before you go thru inspection, then take it off. If TX does random inspections, then you need to plumb the setup similar to what the factory had. Otherwise, the push-in breather cap will work fine, for about $7-8. (Mr Gasket makes a good one. It has a foam filter inside the chrome cap). Good luck! -Dan M.

[gschretter]

I will do that.